An organic light-emitting diode (OLED)/polymer light-emitting diode (PLED) display substrate comprises a glass substrate, an indium tin oxide (ITO) anode, an emitting material layer, and a cathode; the emitting material layer is sandwiched by the thin transparent ITO anode and the metal cathode. When a voltage is applied across the electrodes, holes from the anode are combined with electrons from the cathode on the emitting material layer so as to stimulate organic luminescent material(s) in the emitting material layer to emit light.
Currently, during the preparation of an LED display substrate, a photoresist is coated on a glass substrate; a pixel define layer (PDL) is formed after exposure and development to define a pixel region or pixel regions; and subsequently droplets of a luminescent material is infused into the pixel region by the ink jetprinting method. However, as the dimension of high-resolution pixels of the traditional display substrate is 30 μm×180 μm, the diameter of the droplets formed by ink-jet printing is more than 30 μm, and therefore the dimension of the droplets formed by printing and the pixels are within the same dimension range. In order to guarantee that the droplets formed by printing be smoothly, flatly and completely filled within the pixel region defined by the PDL and prevent the droplets from flowing to adjacent pixel region(s), the wetting characteristic of the surface of the PDL must be improved. Currently, 60% CF4 is mainly used for the fluorination treatment of the surface of the PDL by a chemical vapor deposition (CVD) process, so that the wetting characteristic of the surface of the PDL can be improved. However, as the method requires the additional investment for equipments, the manufacturing costs of the LED display substrate are increased accordingly, which is not advantageous to mass production.